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projector horizontal scan lines?

Discussion in 'Projectors, Screens & Video Processors' started by mark zwern, Aug 25, 2003.

  1. mark zwern

    mark zwern
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    I have purchased a front projector (name unmentioned). I have noticed for about the first 30 minutes of use, until the projector completely warms up. there are noticable horizontal scan lines during verticle panning. After this time period about 98 % of this dissappears. My assumption is a weak scaler. Question, would an external scaler do me any good? Also I am using a high quality progressive scan dvd player.
     
  2. moss

    moss
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    i get exactly the same thing with my panny projector 500 and my harman kardman, ruddy annoying! haven't solved it yet.....the dvd player said something about bad decoding of NTSC to pal may cause it, and allows a tweak to be done but it doesn't help at all!
     
  3. calibos

    calibos
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    How can you expect help if you refuse to tell us what PJ you have??

    If its a Panasonic AE300 then it appears that its an optical effect caused in some way by the smooth screen tech in the PJ because you can 'invoke' the same scanline effect by bobbing your head up and down while staring at the screen. The answer is to defocus slightly and/or sit a little bit farther back.
     
  4. Julia

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    If it's AE300 you can also go into the Service menu and tweak the flicker for the colour screens (the green one is the most problematic).
    I might be wrong, but I think that this scanline artifact (that some say it's particular to all LCDs) disappears with time :).
    I can no longer see it on mine (and apart from the flicker tweak, I've not used anything else, not even defocus).
    Good Luck,

    Julia
     
  5. Monster

    Monster
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    I'm with you on that Julia. Flicker tweak did seem to help and now i do not notice it. However, I suspect if I did not use the PJ for a couple of weeks (Yeah, likley;) ) it wouold be visible again and its just me becoming accustomed to it.
     
  6. Kramer

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    No details about the PJ?? Not been back since asking??

    Strange :confused:

    Horizontal scanline artifact is common to all LCD PJs. I notice it on my HS10 occasionally.

    Not much more to be said unfortunately in the absence of any further details/input.
     
  7. mark zwern

    mark zwern
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    Thanks for all the imput concerning my problem with my horizontal scan lines during verticle panning. I am a new member and assumed after reading the directions, that it was taboo to mention the manafactures name. At any rate the projector is a Panasonic L-300 U. I actually have spoken with gentelman at Panasonic who is in charge of projector development. He actually developed this projector. Needless to say he is quite familar with this unit. He told me some startling news. This problem is common with all of these units. The majority of the artifact dissappears as the unit warms up. He said it is a defect in all of them! I asked him if Panasonic is going to be offering a fix. He said that the new units coming out late 2003 or early2004 will not do this. I said great what about me? I actually had the option of returning this unit and getting something else. I decided to keep it. It has an amazing picture for the money. Thanks again I will try that flicker adjustment.
     
  8. moss

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    I dont wanna sound thicker then I have too :p
    but where EXACTLY is the flicker option in the service menu?

    is it the R G B thing? (I'm using component connection so get that particular set of menus). This seems to adjust colour rather then flicker rates.
     
  9. Kramer

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    We're a pretty liberal bunch around here so mention away :)

    Hope the tweaks mentioned help. Lots of useful info posted on the AE300, try a search here.

    BTW, welcome to the forums ;)
     
  10. moss

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    ladies and gentleman I thank you :)

    my projector had the same thing, changed the green setting and now it is faaaaab!!!!!!!! no flicker at all..........although........it might be in my head but I think the picture is now slightly softer? perhaps..........more investigation needed...............that green screen was pulsing like kryptonite though on the test screen and now its yaaaaaaaaaaho! gone!
     
  11. Marcus Wood

    Marcus Wood
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    I've also noticed horizontal lines on my HS10 - I don't see them all the time, but I see them quite often and I find them the only annoying feature of the HS10, although you can reduce them a lot by defocusing (that's not exactly ideal though).

    They look like scan lines that you get on a widescreen TV when you zoom in on a 4:3 picture to fill the screen. But I thought the point of having an on-board scaler was to get rid of the scan lines.

    So I've been trying to figure out what causes them. At first I thought it could be some kind of scaling artifact, but I don't think it is because I sometimes see it even on Windows, which presumably isn't scaled.

    I can see them on the DVI PC input an on the component input, with all sources (Windows, Sky, Nebula PC terrestrial TV card, DVDs). I don't use the S-video or composite inputs.

    I don't see them all the time - I think I only see them when my eyes are moving vertically. I thnk it might be related to flicker.

    If you look closely at the projected image, the pixels seem to be flickering or moving. Maybe if you move your eyes up or down the screen at a rate that synchronises with this flicker, that causes you to see lines.

    Does anyone know how to reduce/eliminate the effect? I was thinking there might be something you can adjust, like on the Panny AE300.
     
  12. Kramer

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    Nope, no way of eliminating it AFAIK :(

    "Horizontal scan line artifact" as it's known is a common trait of all LCD PJs. No one seems to know whatcouses it but it's not scaling related.

    It's inherent in the PJs - something to do with the way the panels are driven IMO.

    Not a major problem TBH - I notice it infrequently on my HS20. It's about the only element of "picture structure" visible on my PJ so I'm not complaining :)
     
  13. theritz

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    Kramer,


    :D :clap: :smoke:

    Are you sure there isn't something you'd like to tell us ???




    Chat soon.............


    Sean G.
     

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